The present invention relates to a swash plate type compressor, which is equipped with a rotary valve for connecting a cylinder bore that is in a suction stroke to a swash plate chamber.
Japanese Laid-Open Patent Publication No. 5-306680 discloses a swash plate type variable displacement compressor equipped with a rotary valve. The rotary valve is mounted on the circumferential surface of a drive shaft. The outer circumferential surface of the rotary valve includes a variable suction passage. The rotary valve is accommodated in a shaft bore of a cylinder block such that the rotary valve rotates with respect to the cylinder block and moves in the axial direction of the drive shaft. The surface of the cylinder block facing the swash plate chamber includes an inlet groove for drawing in refrigerant gas from the swash plate chamber. The inlet groove communicates with the shaft bore. The cylinder block has cut-out grooves, which connect the shaft bore to the cylinder bores. When any of the cylinder bores is in a suction stroke, refrigerant gas in the swash plate chamber is drawn into the cylinder bore via the inlet groove, the shaft bore, the variable suction passage, and the associated cut-out groove.
In the compressor of the above publication, the inlet groove is open toward a boss of a swash plate, which rotates integrally with the drive shaft. The distance between the boss and the inlet groove is always constant even when the swash plate is rotating. Therefore, during operation of the compressor, rotation of the boss generates stationary vortices in refrigerant between the boss and the inlet groove, which hinders refrigerant gas from being drawn into the inlet groove. As a result, the amount of refrigerant gas drawn into the cylinder bore is suppressed.